1. Field of the Invention.
The present invention relates to fiberization or refining of cellulose, specifically waste paper, to reduce its density to a level wherein it provides a desirable insulation material.
2. Description of the Prior Art.
Various attempts have been made to refine cellulose, such as wood fibers, in paper making operations. For example, U.S. Pat. No. 4,982,482 shows a double disc refiner that has a central rotating disc, and a pair of stationary discs facing this rotating disc on opposite sides and forming a path so that the cellulose will go outwardly with respect to the axis of the rotor on one face of the rotor, and back in toward the axis on the opposite face of the rotor and then will be discharged.
Additionally, a disc type refiner that is similar in construction is shown in U.S. Pat. No. 3,049,307. A particular arrangement of large grooves for the discs is utilized in Patent '307 for obtaining satisfactory operation.
A refiner apparatus is also shown in U.S. Pat. No. 2,654,295, which relates to a particular arrangement of grooves to obtain a movement of fibers in the grooves themselves to work in refining of paper stock.
U.S. Pat. No. 3,815,834 also shows a disc refiner that includes a peripheral flow retarding ring that has a number of flow dividing ribs for regulating the path of movement of fibers being treated. These discs generally work with a slurry of material used in paper pulp manufacture.
U.S. Pat. No. 4,586,665 shows an apparatus for treating cellulose pulp that provides for adjustments of a pair of screw members that are used for treating the pulp by moving the screws or augers on the interior of the housing in which they are mounted.
U.S. Pat. No. 2,858,990 shows a rotor moving relative to a stator, both of which have teeth. The rotor and stator are used for shredding and treating of fibrous material, such as old paper stock and dry pulp sheets.
However, the efficient handling of dry shredded paper flakes and causing them to be broken down into individual fibers to greatly decrease the bulk density, and thereby making the product much more suitable for insulation, has eluded the workers in the field. The present device provides for very precise adjustment of a central rotor moving between two discs, with facing teeth shaped and spaced so that with the flow path of materials, the paper flakes are reduced essentially to individual fibers and the output product is greatly reduced in density.